Inverse Problem For Dirichlet Boundary Value Problems

In this article we consider Sturm-Liouville operator with $q\in W_{1}^{2}[0,1]$andDirichletboundaryconditions\mathrm{.}Weprovethatiftheset${(n\pi)^{2}:n\in $\mathbb{N}$}$ is a subset of the spectrum of the Sturm-Liouville operator with Dirichlet boundary conditions, then $q=0$ a.e.